Microcontroller-based multifunctional electronic switch and lighting apparatus having the same

ABSTRACT

An inter-linkable LED security light is disclosed which is configured with an LED load, a detection device, a switching circuitry, a microcontroller and a wireless transmitter. When an external control signal is detected by the detection device, the external control signal is converted into a message carrying sensing signal and the microcontroller responsively operates to output a control signal to turn on the security light for a predetermined time duration, synchronously the microcontroller also manages to transmit the message sensing signal thru the wireless transmitter to control the same lighting performance of at least one neighboring light. The detection device is optionally an active infrared ray motion sensor, a passive infrared ray motion sensor, an ultrasonic wave sensor, a microwave sensor capable of detecting a motion intrusion or a photo sensor capable of detecting a light intensity of a detection area where the lighting apparatus is positioned.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation application of prior application Ser.No. 15/702,871 filed on Sep. 13, 2017, currently pending, the entirecontents of which are incorporated herein by reference. The priorapplication Ser. No. 15/702,871 filed on Sep. 13, 2017 is a continuationapplication of prior application Ser. No. 15/161,902 filed on May 23,2016, now U.S. Pat. No. 9,795,007. The prior application Ser. No.15/161,902 filed on May 23, 2016 is a continuation application of priorapplication Ser. No. 14/579,174 filed on Dec. 22, 2014, now U.S. Pat.No. 9,380,680 B2, the prior application Ser. No. 14/579,174 filed onDec. 22, 2014 is a continuation application of U.S. Pat. No. 8,947,000B2.

BACKGROUND 1. Technical Field

The present disclosure relates to a technology using a microcontrollerwith program codes designed to provide a user friendly solution forperforming on/off switch control, diming control, and timer managementfor a lighting apparatus or an electrical appliance.

2. Description of Related Art

A mechanical-type electric switch is a manually operatedelectromechanical device. Its function is based on attaching ordetaching two metal conductors to produce a short or open circuit,respectively. This mechanical-type switch is not suitable for installingin a space where has the concern of gas explosion, because aninstantaneous surge current, produced by suddenly engaging or releasingthe metallic contact of the switch, may generate electric sparks toignite fire.

A controllable semiconductor switching element, such as a triac, hasnearly zero voltage between two output-electrodes in conduction mode andnearly zero current through two output-electrodes in cut-off mode. Solidstate electronic switch utilizing the above unique features of triac forcircuit on/off switch control can avoid generating electric arc, sincethe main current pathway of the solid-state switch is not formed byengaging the two metal conductors. It becomes a much better choice thanmechanical-type electric switch from the stand point of safetyconsideration.

Solid-state electronic switches are constructed with various methods totrigger controllable switching element, like triac or thyristor, intoconduction or cutoff for desired electric power transmission. Forexample, U.S. Pat. No. 4,322,637 disclosed a technique using opticalcoupling element to control bi-directional thyristor or triac inconduction or off state; or another U.S. Pat. No. 6,285,140B1 discloseda technique using microcontroller incorporated with zero-crossing-pointdetector to generate AC-synchronized time-delay pulse to control triacin on or cut-off state so as to transmit variable electric power to alight-emitting diode load.

Mostly a mechanical toggle or spring button of similar setup is usuallyapplied on the electronic switch to facilitate manual on/off switchoperation. The operation of electronic switch with mechanical togglemeans an inevitable contact by hand which is not appropriate in workingplaces such as kitchens or hospitals. To relieve concerns of contagionor contamination resulted through hand contacts, touchless switches aredeveloped. For example, U.S. Pat. No. 5,637,863 disclosed a techniqueutilized infrared sensor to activate electronic switch to operate on/offswitch control, and even dimming control presumably by modifying itscircuit design.

In retrospect, the above mentioned prior arts have however still somedrawbacks. For instance, U.S. Pat. No. 5,637,863 used a complicatedinfrared sensor construction and circuit design; or U.S. Pat. No.6,285,140B1 did not resort to an efficient control of electric powertransmission from power source to various electric impedances which isrequired in lighting apparatus.

SUMMARY

An exemplary embodiment of the present disclosure provides amultifunctional electronic switch which utilizes a microcontroller toperform at least two functions, which are on/off switch control anddimming control or power transmission level control, for a lightingapparatus or an electric appliance. The multifunctional electronicswitch comprises a microcontroller, a detection means and a controllablesemiconductor switching element. The controllable semiconductorswitching element is connected between a load and a power source in aserial fashion. The detection means detects an external control signaland converts the outcome into message carrying low voltage sensingsignals readable to the microcontroller. The microcontroller operatesaccording to specific format of the sensing signals the controllablesemiconductor switching element in on/off switch mode or in dimmingcontrol mode so as to transmit whole/zero electric power, or to transmitdimmed electric power, from the power source to the load.

An exemplary embodiment of the present disclosure provides amicrocontroller based electronic switch for detecting an externalcontrol signal. The microcontroller based electronic switch comprises adetection means, a microcontroller, and a controllable switchingelement. The controllable switching element is electrically connectedbetween a power source and a load. The detection means is used fordetecting the external control signal played by the user and convertingthe external control signal into a message carrying sensing signal. Themicrocontroller with program codes written and designed to read andinterpret the message carrying sensing signal generated by the detectionmeans, wherein the microcontroller is electrically connected between thecontrollable switching element and the detection means. Themicrocontroller controls the conduction state or cutoff state of thecontrollable switching element according to the message carrying sensingsignal generated by the detection means. When the controllable switchingelement is in a conduction state, the microcontroller further controlselectric power transmission level from the power source to the loadaccording to the time length of the message carrying sensing signalreceived from the detection means.

An exemplary embodiment of the present disclosure provides amicrocontroller based electronic switch connected between a load and aDC power source. The microcontroller based electronic switch controlsthe conduction rate between the load and the DC power source. Themicrocontroller based electronic switch comprises a detection means, amicrocontroller, and an uni-directional controllable semiconductorswitching element. The uni-directional controllable semiconductorswitching element is connected between the load and the DC power source.The detection means is used for detecting the external control signalplayed by the user and converting said external control signal into amessage carrying sensing signal. The microcontroller is connectedbetween the uni-directional controllable semiconductor switching elementand the detection means. The microcontroller produces apulse-width-modulation voltage signal according to the message carringsensing signal, so as to control a conduction or cut-off state of theuni-directional controllable semiconductor switching element. When theuni-directional controllable semiconductor switching element is inconduction state, the microcontroller controls electric powertransmission level according to the message carrying sensing signal,wherein the electric power is supplied to the load from the DC powersource.

An exemplary embodiment of the present disclosure provides amicrocontroller based electronic switch connected between a load and anAC power source. The microcontroller based electronic switch controlsthe conduction rate between the load and the AC power source. Themicrocontroller based electronic switch comprises a detection means, amicrocontroller, a zero-crossing-point detector and a bi-directionalcontrollable semiconductor switching element. The bi-directionalcontrollable semiconductor switching element is connected between theload and the AC power source. The detection means is used for detectingthe external control signal played by the user and converting saidexternal control signal into a message carrying sensing signal. Thezero-crossing-point detector is connected between the microcontrollerand the AC power source. The microcontroller is connected, respectively,to the detection means, the zero-crossing-point detector, and thebi-directional controllable semiconductor switching element. Themicrocontroller generates zero-crossing-point time-delay pulse or zerovoltage, respectively, to control the conduction or cut-off state of thebi-directional controllable semiconductor switching element according tothe message carrying sensing signal. When the bi-directionalcontrollable semiconductor switching element is in conduction state, themicrocontroller controls electric power transmission level according tothe time length of the message carrying sensing signal, wherein theelectric power is supplied to the load from the AC power source.

To sum up, the present disclosure is characteristic in, a touch less ora direct touch interface between the user and the multifunctionalelectronic switch is created to implement at least two operation modesof the electronic switch by using software codes written in OTPROM(one-time programmable read only memory) of microcontroller to analyzethe message carrying low voltage sensing signals.

In order to further understand the techniques, means and effects of thepresent disclosure, the following detailed descriptions and appendeddrawings are hereby referred, such that, through which, the purposes,features and aspects of the present disclosure can be thoroughly andconcretely appreciated; however, the appended drawings are merelyprovided for reference and illustration, without any intention to beused for limiting the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the present disclosure and, together with thedescription, serve to explain the principles of the present disclosure.

FIG. 1 is a block diagram of a microcontroller based electronic switchusing an infrared ray sensor as a detection means applied for an ACpower source according to an exemplary embodiment of the presentdisclosure.

FIG. 2 is a circuit diagram of a microcontroller based electronic switchusing an infrared ray sensor applied for an AC power source according toan exemplary embodiment of the present disclosure.

FIG. 3A is a schematic diagram showing a practical operation of aninfrared ray sensor associated with a microcontroller based electronicswitch according to an exemplary embodiment of the present disclosure.

FIG. 3B is a waveform diagram showing a low voltage sensing signalaccording to an exemplary embodiment of the present disclosure.

FIG. 4 is a flow chart of a program executed in a microcontroller basedelectronic switch according to an exemplary embodiment of the presentdisclosure.

FIG. 5 is a voltage waveform diagram of a microcontroller basedelectronic switch when the electronic switch operating in the on/offswitch control mode is in cut-off state according to an exemplaryembodiment of the present disclosure.

FIG. 6 is a voltage waveform diagram of a microcontroller basedelectronic switch when the electronic switch operating in the on/offswitch control mode is in conduction state according to an exemplaryembodiment of the present disclosure.

FIG. 7 is a voltage waveform diagram of a microcontroller basedelectronic switch operating in the dimming control mode according to anexemplary embodiment of the present disclosure.

FIG. 8A is a block diagram of a microcontroller based electronic switchfor a DC power source according to an exemplary embodiment of thepresent disclosure.

FIG. 8B is a voltage waveform diagram of the pulse width modulationvoltage signal according to an exemplary embodiment of the presentdisclosure.

FIG. 9 is a block diagram of a microcontroller based electronic switchfor AC power source according to another one exemplary embodiment of thepresent disclosure.

FIG. 10A is an application diagram of a traditional popular piece ofunder cabinet light with LED as light source.

FIG. 10B is an application diagram of an exemplary embodiment of thepresent disclosure for a LED under cabinet light featured with atouchless interface between the user and the under cabinet light.

FIG. 10C is an application diagram of an exemplary embodiment of thepresent disclosure for a wall switch construction electrically connectedto a ceiling light for the performance of three working modes.

FIGS. 11A, 11B, 11C and 11D schematically and respectively show V-Irelationship charts (Forward Current vs. Forward Voltage) for a whiteLED chip from each of 4 different LED manufacturers.

FIG. 12 is a data sheet showing data of the minimum forward voltages andmaximum forward voltages collected from various LED manufacturers.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

Referring to FIG. 1, FIG. 1 is a block diagram of a microcontrollerbased electronic switch using an infrared ray sensor as a detectionmeans applied for an AC power source according to an exemplaryembodiment of the present disclosure. A microcontroller based electronicswitch 1 is connected in series to an AC power source 3, and is furtherconnected to a load 2, so as to control AC power delivered to the load2. The microcontroller based electronic switch 1 comprises at least aninfrared ray sensor 11, a microcontroller 12, a zero-crossing-pointdetector 13, and a bi-directional controllable semiconductor switchingelement 14. The infrared ray sensor 11 is connected to one pin ofmicrocontroller 12 to transmit a low voltage sensing signal to themicrocontroller 12. The zero-crossing-point detector 13 is connected toanother pin of microcontroller 12 and is also electrically coupled tothe AC power source 3 to produce AC power synchronized signals which arefed to the microcontroller 12. The microcontroller 12 through its onedesignated pin is electrically connected to the control electrode of thebi-directional controllable semiconductor switching element 14 so asusing appropriate conduction phase to control the electrical conductionstate of the bi-directional controllable semiconductor switching element14.

The infrared ray sensor 11 detects object motions coming from the userand converts the detected result into message carrying low voltagesensing signals readable to the microcontroller 12. The microcontroller12 decodes the low voltage sensing signals (message carrying low voltagesensing signals) according to the program designed and written in itsOTPROM (one-time programmable read only memory) memory. Themicrocontroller 12 is with program codes written and designed to readand interpret the message carrying sensing signal generated by theinfrared ray sensor 11. The infrared ray sensor 11 is an exemplaryembodiment for a detection means to detect the external motion signalplayed by the user and convert the external motion signal into a messagecarrying sensing signal. The microcontroller 12 recognizes the workingmode that the user has chosen and proceeds to execute the correspondingloop of subroutine for performance. Each working mode is defined in thesoftware codes with loops of subroutine for execution.

One working mode is on/off switch control mode. In this working mode,according to the low voltage sensing signal from the infrared ray sensor11, the microcontroller 12 operates the bi-directional controllablesemiconductor switching element 14 in conduction state or cut-off statealternatively. More specifically, in this working mode, together withthe zero-crossing-point detector 13, the microcontroller 12 generatesvoltage pulses synchronized with the AC power source 3 to trigger thebi-directional controllable semiconductor switching element 14 to be inconduction state, such that a fixed electric power can be sent to theload 2; or the microcontroller 12 generates a zero voltage to set thebi-directional controllable semiconductor switching element 14 to be incut-off state, and thereby ceases to transmit the fixed electric powerto the load 2.

Another working mode is dimming control mode about controlling differentlevels of electric power transmission to the load 2 by controlling theconduction rate of the bi-directional controllable semiconductorswitching element 14. Using the synchronized signals produced by thezero-crossing-point detector 13 as a reference, the microcontroller 12generates phase delay voltage pulses synchronized with the AC powersource 3 to trigger the conduction of the bi-directional controllablesemiconductor switching element 14 to transmit electric power to theload 2. Responding to the low voltage sensing signals from the infraredray sensor 11, the microcontroller 12 continuously changes the phasedelay time of the triggering pulses during each cycle period of the ACpower source 3. Consequently, the conduction rate of the bi-directionalcontrollable semiconductor switching element 14 is gradually changed.The power level of the load 2 is therefore managed by the low voltagesensing signals from the infrared ray sensor 11 which are generatedaccording to the user's intention, wherein when the bi-controllablesemiconductor switching element 14 is in conduction state, themicrocontroller further controls the electric power transmission levelfrom the AC power source 3 to the load 2 according to low voltagesensing signals from the infrared ray sensor 11.

Referring to FIG. 1 and FIG. 2, FIG. 2 is a circuit diagram of amicrocontroller based electronic switch applied for an AC power sourceaccording to an exemplary embodiment of the present disclosure. Themicrocontroller based electronic switch 1 is connected through abi-directional controllable semiconductor switching element 14 to the ACpower source 3 and the load 2 in a serial fashion. A voltage VDD for thecircuit system is generated by conventional voltage reduction andrectification from the AC power 3. The output stage of the infrared raysensor 11 is a transistor M2. The drain of the transistor M2 isconnected to a pin pin_3 of the microcontroller 12 to deliver lowvoltage sensing signals to the microcontroller 12.

The zero-crossing-point detector 13 is composed of a transistor Q1 and adiode D3. The collector of the transistor Q1 is connected to a pinpin_10 of the microcontroller 12, the base of the transistor Q1 isconnected to a conducting wire of the AC power source 3 through thediode D3 and a resistor R3. In the positive half-cycle for AC powersource 3, the transistor Q1 is saturated conducting, and the voltage atthe collector of the transistor Q1 is close to zero. In the negativehalf-cycle for AC power source 3, the transistor Q1 is cut-off, and thevoltage at the collector of the transistor Q1 is a high voltage of VDD.Corresponding to the sine wave of the AC power source 3, thezero-crossing-point detector 13 generates therefore signals of squarewave alternatively with a low voltage and a high voltage through thecollector of the transistor Q1. The square wave is synchronized with theAC power source 3 and sent to a pin pin_10 of the microcontroller 12 forthe purpose of controlling conduction phase, and the details thereof aredescribed later. In practice, the bi-directional controllablesemiconductor switching element 14 can be a triac T1, the pin pin_1 ofthe microcontroller 12 is connected to the gate of the triac T1 tocontrol the conduction or cut-off state of the triac T1, or to controlthe conduction rate of the triac T1.

Still referring to FIG. 2, the infrared ray sensor 11 comprises atransmitting circuit and a receiving circuit. In the transmittingcircuit, an infrared light-emitting diode IR_LED is connected to thedrain of the transistor M1 in a serial fashion, and the gate of thetransistor M1 is connected to an output of the timer 110. In practice,the timer 110 can be a 555 timer IC. The 555 timer IC generates asquare-wave with a frequency of about 3 kHz to modulate the draincurrent of the transistor M1, such that the infrared light-emittingdiode IR_LED provides an infrared light signal with a square wave formwhich is severed as the light source of the infrared ray sensor.

The receiving circuit is an infrared light detection circuit andcomprises a photosensitive diode PD, two serially connected amplifiers112, 114, and a transistor M2. The drain of the transistor M2 isconnected to a pin pin_3 of the microcontroller 12. In practice, theamplifiers 112 and 114 can be LM324 operational amplifier. Thecombination of the amplifier 114 and resistors R7 through R10 is aSchmitt trigger circuit having a threshold voltage, and the thresholdvoltage is produced by the voltage divider composed by resistors R8 andR9. The Schmitt trigger circuit makes possible a high discrimination ofa true detection to a false one.

The photosensitive diode PD is used to receive the infrared light signalfrom the transmitting circuit. If the output voltage of the amplifier112 exceeds the threshold voltage, the amplifier 114 produces a highvoltage applied to the gate of the transistor M2, such that thetransistor M2 is turned on. Therefore, the drain of the transistor M2provides a low voltage sensing signal which is close to zero voltage,and the time length of the low voltage sensing signal is related to thetime period the infrared ray is detected.

In addition, if the photosensitive diode PD does not receive theinfrared light signal, the output voltage of the amplifier 112 is lowerthan the threshold voltage, and then the amplifier 114 provides a lowvoltage to the gate of the transistor M2, such that the transistor M2 isturned off. Therefore, the drain of the transistor M2 provides a highvoltage of VDD. In other words, the pin pin_3 of the microcontroller 12receives either a low voltage sensing signal or a high voltage dependingon whether the infrared ray sensor 11 detects the infrared light or not,wherein the time length of the low voltage sensing signal is about thetime period within which the infrared light is detected.

In other words, the infrared ray sensor 11 generates a sensing signalwhich is characterized by a low voltage within a time length. Thesensing signal with a specific time length of low voltage can beconsidered as a sensing signal format which carries message to make themicrocontroller 12 to operate in one of at least two working modesaccordingly, wherein one working mode is on/off switch control mode andthe another one is dimming control mode to control the conduction rateof the bi-directional controllable semiconductor switching element 14.Referring to FIG. 2, FIG. 3A and FIG. 3B, FIG. 3A is a schematic diagramshowing a practical operation of an infrared ray sensor associated witha microcontroller based electronic switch according to an exemplaryembodiment of the present disclosure, and FIG. 3B is a waveform diagramshowing a low voltage sensing signal according to an exemplaryembodiment of the present disclosure. In FIG. 3A, the infraredlight-emitting diode IR_LED is parallel arranged to the photosensitivediode PD without accurate alignment. When an object, here is a humanhand, moves in front of the infrared light-emitting diode IR_LED, theinfrared light emitted from the infrared light-emitting diode IR_LEDscatters from the object surface onto the photo sensing surface of thephotosensitive diode PD.

FIG. 3B shows a waveform of the low voltage sensing signal provided fromthe infrared ray sensor 11. If the photosensitive diode PD does notreceive the infrared light scattered from the target object surface, orthe intensity of the infrared light received by the photosensitive diodePD is insufficient, the drain of the transistor M2 provides a highvoltage H of VDD. Within an appropriate distance, the photosensitivediode PD receives the infrared light scattered from the object surface,and the intensity of the received infrared light is enough to cause theoutput voltage of the amplifier 112 exceeding the threshold voltage, theamplifier 114 produces a high voltage, such that the transistor M2 isturned on, and the drain of the transistor M2 provides a signal with alow voltage L of about zero volt. In other words, when the infrared raysensor 11 detects an object, most commonly user's hand, purposefullyentering the infrared ray detecting zone, the infrared ray sensor 11generates a low voltage sensing signal, by contrast when an object isnot within the infrared ray detecting zone, the infrared ray sensor 11generates a high voltage. The infrared ray sensor 11 comprising a meansfor emitting infrared light to form the defined infrared ray detectingzone, a means for detecting infrared light reflected from the objectmoving into the infrared ray detecting zone.

The appropriate distance or the infrared ray detecting zone is definedas an effective sensing range or area of the infrared ray sensor 11. InFIG. 3B, the time length Ts of the low voltage L is approximately equalto the time period that an object stays within the infrared raydetecting zone, wherein the time period is about a few tenths through afew seconds. When the object leaves the infrared ray detecting zone, thesignal delivered from the infrared ray sensor 11 changes from a lowvoltage L to a high voltage H, as shown in FIG. 3B. Hence the sensingsignal generated from the infrared ray sensor 11 is a binary signalreadable to the program written in the OTPROM memory of themicrocontroller 12. The microcontroller based electronic switch 1utilizes specific sensing signal format characterized by the time lengthTs of the low voltage sensing signal to implement at least twofunctions, namely, on/off switch control and dimming control. Byintroducing a preset time To, the microcontroller 12 can executesubroutine corresponding to the functions of the on/off switch controland the dimming control determined by a comparison scheme of the timelength Ts with the preset time To. The user can therefore operates themicrocontroller-based electronic switch 1 in a convenient manner simplyby moving his hand into or out of the infrared ray detecting zone of theinfrared ray sensor 11, and staying his hand there for a time period toselect desired performance function.

Referring to FIG. 2, FIG. 3 and FIG. 4, FIG. 4 is a flow chart of aprogram executed in a microcontroller of a microcontroller basedelectronic switch according to an exemplary embodiment of the presentdisclosure. The program written in the OTPROM memory of themicrocontroller 12 includes several subroutine loops. These loops arestarted from the loop of steps S1 through S6 of the on/off switchcontrol mode, and may jump into the loop of steps S8 through S10 of thedimming control mode according to the time length Ts of the low voltagesensing signal. The pin pin_3 of the microcontroller 12 receives a highvoltage H or a low voltage L from the infrared ray sensor 11, whereinthe time length Ts of the low voltage sensing signal is about the timelength which the user's hand stays within the infrared ray detectingzone.

The program of the microcontroller 12 starts its execution from the loopof steps S1 and S2 in which the microcontroller based electronic switch1 is off. The program of the microcontroller 12 scans the voltage at thepin pin_3 of the microcontroller 12. If the voltage at the pin pin_3 ofthe microcontroller 12 is high (bit 1), the program of themicrocontroller 12 stays in the loop of steps S1 and S2 that themicrocontroller based electronic switch 1 is off. On the contrary, ifthe voltage at the pin pin_3 is low (bit 0), the program of themicrocontroller 12 jumps into the loop of steps S3 through S6 in whichthe microcontroller based electronic switch 1 is on. At step S4 when themicrocontroller based electronic switch 1 is on, the program of themicrocontroller 12 scans the voltage at the pin pin_3 of themicrocontroller 12. If the voltage at the pin pin_3 of themicrocontroller 12 is low (bit 0), the program of the microcontroller 12jumps to step S5 to compare the time length Ts with a preset time To. Inpractice, the preset time To is between 1 through 3 seconds, but thepresent disclosure is not limited thereto.

At step S5, the program of the microcontroller 12 check the time lengthTs, if Ts is shorter than the preset time To, step S5 proceeds to stepS6 to detect whether the voltage at the pin pin_3 is momentary a highvoltage H (bit 1). At step S6, if the voltage at the pin pin_3 is thevoltage H, the program goes back to the loop of steps S1 and S2 in whichthe microcontroller based electronic switch 1 is off. At step S6, if thevoltage at the pin pin_3 is low, the program remains in the loop ofsteps S3 through S6 in which the microcontroller based electronic switch1 is on.

To sum up, the on/off switch control mode is described by the loopsconsisting of steps S1 through S6 that the microcontroller basedelectronic switch 1 is operated in off- and on-state rotationally. Themicrocontroller based electronic switch 1 is on or off according towhether the user moves his hand into and then pulls out the infrared raydetecting zone of the infrared ray sensor 11 within the preset time To.

At step S5, the program of the microcontroller 12 check the time lengthTs, if the time length Ts is longer than the preset time To, the programjumps to step S7 to detect whether the time length Ts is longer than ntimes the preset time To (n≥2). At step S7, if the time length Ts is notlonger than n times the preset time To, the program goes back to theloop of steps S3 through S6 that the microcontroller based electronicswitch 1 remains on. At step S7, if the time length Ts is longer than ntimes the preset time To, the program jumps into a loop consisting ofsteps S8 through S10 to execute a subroutine for the dimming controlmode of microcontroller based electronic switch 1. FIG. 4 does not showthe details of subroutine associated with the dimming control mode, butthe process is described in short as follows. At step 9, the program ofthe microcontroller 12 scans the voltage at the pin pin_3 of themicrocontroller 12. The program proceeds to step 10 from Step 9, if thevoltage at the pin pin_3 is low. At step 10, the subroutine of themicrocontroller 12 checks if Ts>nTo. If the voltage at the pin pin_3 islow for several times, and the time lengths denoted by Ts or Ts' areshorter than n times the preset time To, the subroutine remains in therotation loop defined by step 8 through S10, and microcontroller 12continuously increases or decreases the electric power transmission tothe load 2 by controlling the conduction rate. If the electric power ofthe load 2 reaches the maximum or minimum electric power, the program ofthe microcontroller 12 responds no more to the low voltage sensingsignal. At step 10, if the time length Ts is longer than n times thepreset time To, the program of the microcontroller 12 jumps back to theloop of steps S1 and S2 in which the microcontroller based electronicswitch 1 is off. Then, the program of the microcontroller 12 resumesitself from steps S1 and S2 in a rotational manner to execute thesubroutines represented by the steps shown in FIG. 4.

In the exemplary embodiment of FIG. 2, the preset time To and the numbern can be set 2 seconds and 2, respectively. Referring to the stepsexecuted by the microcontroller 12 in FIG. 4, if the detected timelength Ts of the low voltage sensing signal at the pin pin_3 is lessthan 2 seconds, that means the time period which the hand stays withinthe infrared ray detecting zone is less than 2 seconds, themicrocontroller 12 remains in the current function mode. If the detectedtime length Ts at the pin pin_3 is longer than 4 seconds, that means thetime length which the hand stays within the infrared ray detecting zoneis longer than 4 seconds, the microcontroller 12 changes the currentfunction mode to another one function mode. In other words, if the timelength Ts of the low voltage sensing signal is shorter than the presettime To, the microcontroller 12 operates either in on/off switch mode orin dimming mode. If the detected time length Ts of the low voltagesensing signal is longer than n times the preset time To, themicrocontroller 12 changes its program execution from the on/off switchmode into the dimming control mode and vice versa.

In addition, the concept of the present disclosure can be furtherextended to implement a multifunctional electronic switch having atleast three functions built in one, which are on/off switch control,dimming control and timer management. The program written in the OTPROMmemory of the microcontroller can be modified in such a manner that themicrocontroller responds not only to the low voltage sensing signal ofthe infrared ray sensor, but also to a specific sequence of the sensingsignals. The microcontroller executes subroutines of working modescorresponding to the said three functions according to the detected timelength Ts and special sequence of the low voltage sensing signals. Thefirst working mode is on/off switch control mode used to control theconduction or cut-off state of the controllable semiconductor switchingelement. The second working mode is dimming control mode used to controlthe conduction rate of the controllable semiconductor switching element.The third working mode is timer management mode used to momentarilydelay and gradually turn off the controllable semiconductor switchingelement. When the infrared ray sensor generates a low voltage sensingsignal within the preset time To, the microcontroller operates in theon/off switch mode by controlling the conduction or cut-off state of thecontrollable semiconductor switching element alternately. If the timelength Ts of the low voltage sensing signal is longer than n times thepreset time To, the microcontroller changes its operation from theon/off switch control mode to the dimming control mode. Once in thedimming control mode, the microcontroller executes subroutine togradually change the conduction rate of the controllable semiconductorswitching element from the maximum conduction rate to the minimumconduction rate, and then to gradually change the conduction rate fromthe minimum conduction rate to the maximum conduction rate forcompleting a dimming cycle. In the dimming cycle, the moment when theinfrared ray sensor provides a high voltage is a dimming end point.According to the dimming control mode design, the microcontroller locksthe conduction rate of the controllable semiconductor switching elementat the dimming end point. Thereafter, if the infrared ray sensorgenerates a plurality of low voltage sensing signals, for instance, aplural signal of two consecutive sensing signals, each within the presettime To, the microcontroller operates in the timer management mode byexecuting a subroutine to momentarily delay and gradually to turn offthe controllable semiconductor switching element. It is clear to see theadvantage of the present disclosure to integrate various switch controlfunctions in one without changing the hardware circuit design. All aresimply done by defining the format of sensing signals and by modifyingthe program written in the OTPROM memory in the microcontroller.

Refer to FIG. 5, FIG. 6 and FIG. 7 in accompanying FIG. 2 and FIG. 4.According to an exemplary embodiment of the present disclosure, FIG. 5is a voltage waveform diagram of a microcontroller based electronicswitch in cut-off state when operating in on/off switch control mode,FIG. 6 is a voltage waveform diagram of a microcontroller basedelectronic switch in conduction state when operating in on/off switchcontrol mode, and FIG. 7 is a voltage waveform diagram of amicrocontroller based electronic switch when operating in dimmingcontrol mode. In FIG. 5, FIG. 6, and FIG. 7, the voltage waveforms asshown from the top are, respectively, a sine wave output from the ACpower source 3, an output signal of the zero-crossing-point detector 13that is fed to pin pin_10 of the microcontroller 12, an output signalfrom the pin pin_1 of the microcontroller 12, and a voltage waveformbetween the two ends of the load 2. The voltage waveforms are used todescribe the interactions related to the program of the microcontroller12 and the microcontroller based electronic switch 1 in the abovementioned two working modes. As already described above, the voltagesignal generated by the zero-crossing-point detector 13 is a square wavewith a low and a high voltage, which is fed to the pin pin_10 of themicrocontroller 12 and, to be explained later, served as an externalinterrupt trigger signal. The voltage signal from the pin pin_1 of themicrocontroller 12 is sent to the gate of the triac T1 to control theconduction state of the triac T1.

In the program loops corresponding to the on/off switch control mode andthe dimming control mode, the microcontroller 12 utilizes the externalinterrupt control technique to generate voltage pulses synchronized withAC power. To accomplish it, the program of the microcontroller 12 has asetup with the voltage level variations at the pin pin_10 as externalinterrupt trigger signals. Since the time point of high or low voltagelevel variation in the signal generated by the zero-crossing-pointdetector 13 is the zero crossing point of AC sine wave, the externalinterrupt process is automatically triggered at the zero crossing pointof the AC power source 3, and the related meaning of the details arefurther described in FIG. 6 and FIG. 7.

Referring to FIG. 5 in accompanying FIG. 2 and FIG. 4, the program ofthe microcontroller 12 starts from the loop of steps S1 and S2 of on/offswitch control mode, wherein the microcontroller based electronic switch1 is off. The program of the microcontroller 12 scans the voltage at thepin pin_3. If the voltage at the pin pin_3 is a high voltage, themicrocontroller 12 generates a zero voltage at the pin pin_1, which isfed to the gate of the triac T1 to turn it off. For no current flowingthrough the triac T1, the voltage between the two ends of the load 2 iszero in each AC cycle.

Refer to FIG. 6 in accompanying FIG. 2 and FIG. 4. If the program of themicrocontroller 12 detects a low voltage at the pin pin_3, the programof microcontroller 12 jumps to steps S3 and S4 of on/off switch controlmode, wherein the microcontroller based electronic switch 1 is on. Themicrocontroller 12 scans within a few microseconds the voltage at thepin pin_10. The external interrupt happens in each AC half cycle (ofsome milliseconds) at the time point of voltage level variation in thesquare wave signal. In the external interrupt process, no other programis executed, instead the program is commanded to go back to the mainprogram instantly. The program of the microcontroller 12 is designedbased on the time point when the external interrupt occurs, which isalso the zero crossing point of the AC power source 3. After a delaytime tD with respected to the time point of the external interrupt, theprogram of the microcontroller 12 generates a zero-crossing-pointtime-delay pulse at the pin pin_1. The signal provided from the pinpin_1 is a zero-crossing-point time-delay pulse having a delay time tDafter the zero crossing point of AC power. The zero-crossing-pointtime-delay pulse is generated both in the positive and negativehalf-cycle of the AC power source 3, and used to trigger insynchronization with AC power source 3 the triac T1 into conduction,such that the AC power source 3 delivers in each half AC cycle equalelectric power to the load 2 which is in proportion to a conduction timeton of the triac T1. In contrast with the AC power source 3 and the zerocrossing point delay pulse, the voltage waveform on the load 2 isdepicted in FIG. 6, and the conduction time ton is designated.

In the loop of steps S3 and S4 of the microcontroller based electronicswitch 1 being on, the delay time tD of the zero-crossing delay voltagepulse is a fixed value to make a constant average electric powerdelivered to the load 2. By designing a minimum time delay tD, theconduction time ton of the triac T1 can reach the maximum to make themaximum electric power transmission to the load 2. If the load 2 is anelectric light source and the microcontroller based electronic switch 1is alternatively switched in the conduction or cut-off state, the lightsource emits respectively the darkest or the brightest luminance. Inpractice, the load 2 can be an incandescent bulb, a fluorescent light,an AC LED diode or a light emitting diode module. If the load 2 is alight emitting diode module, the light-emitting diode module isconnected between output ports of a full-wave rectification bridge.

Refer to FIG. 7 in accompanying FIG. 2 and FIG. 4. In the loop of stepsS3 through S6, the microcontroller based electronic switch 1 is on, theprogram of the microcontroller 12 scans the voltage at the pin pin_3. Ifthe sensing signal fed to the pin pin_3 is a low voltage with the timelength Ts longer than nTo (n>2), the program of the microcontroller 12jumps to the loop of steps S8 through S10 for executing the dimmingcontrol mode. When the microcontroller based electronic switch 1 is inthe dimming control mode, the program of the microcontroller 12 scansthe voltage at the pin pin_10, so as to generate a zero-crossing-pointtime-delay pulse with a delay time tD at the pin pin_1. Simultaneously,the program of the microcontroller 12 scans the voltage at the pinpin_3. If the detected sensing voltage at the pin pin_3 is a low voltagewith different time length Ts, the program continuously increases thedelay time tD of the zero-crossing-point time-delay pulse in proportionto the time length Ts. If the delay time tD reaches the maximum, theprogram of the microcontroller 12 responds no more to the detected lowvoltage at the pin pin_3. When the delay time tD is increased, theconduction time ton of triac T1 is decreased as shown in FIG. 7. Theaverage electric power delivered to the load 2 is thus accordinglyreduced. In FIG. 7, the voltage waveforms are depicted to show that theprogram of the microcontroller 12 shifts the delay time tD step by stepcorresponding to the low voltage sensing signal when the microcontrollerbased electronic switch 1 operates in the dimming control mode.

In practice, the load 2 can be a light-emitting diode, especially,AC-LED. The AC-LED has a cut-in voltage V_(t) for conducting current.During a sinusoidal period of the AC power source 3, if the voltagemagnitude of the AC power source is still lower than the cut-in voltageV_(t) of the load 2 and when the pin pin_1 provides azero-crossing-point time-delay pulse, the bi-directional controllablesemiconductor switching element 14 cannot be triggered stably intoconduction. Therefore, by designing the zero-crossing-point time-delaypulse as shown in FIG. 6 and FIG. 7, the cut-in voltage V_(t) of theload 2 should be considered. Thus, to ensure that the bi-directionalcontrollable semiconductor switching element 14 can be triggered stably,it is necessary to limit the delay time tD in an appropriate range asfollows:

t _(o) <tD<1/(2f)−t _(o),

wherein t_(o)=(½πf)sin⁻¹(V_(t)/V_(m)), f is the frequency and V_(m) isthe voltage amplitude of the AC power source 3. The knowledge for stabletriggering provides mean for accurate design of the zero-crossing-pointtime-delay pulse that enables an efficient electric power transmissionfrom the AC power source to the load 2 which may have specific impedanceor threshold voltage.

In addition, the concept of the present disclosure can also be appliedto the DC power source, wherein the controllable semiconductor switchingelement and the program of the microcontroller 12 should be modifiedslightly, and the zero-crossing-point detector should be removed.Referring to FIG. 8A, FIG. 8A is a block diagram of a microcontrollerbased electronic switch 1′ using an infrared ray sensor as a detectionmeans for a DC power source according to an exemplary embodiment of thepresent disclosure. The microcontroller based electronic switch 1′ isconnected to a DC power source 3′ and a load 2′ in a serial fashion, soas to control the electric power of the DC power source 3′ delivered tothe load 2′. Compared to FIG. 1, the microcontroller based electronicswitch 1′ in FIG. 8A comprises an infrared ray sensor 11′, amicrocontroller 12′, and a uni-directional controllable semiconductorswitching element 14′. In practice, the uni-directional controllablesemiconductor switching element 14′ can be a bipolar junction transistor(BJT) or a metal-oxide-semiconductor field-effect transistor (MOSFET).The load 2′ can be a light-emitting diode or an incandescent bulb, butpresent disclosure is not limited thereto.

Referring to FIG. 3 and FIG. 8B, the infrared ray sensor 11′ detects auser's hand, for instance, and converts the outcome into messagecarrying low voltage sensing signals readable to the microcontroller12′. The microcontroller 12′ decodes the low voltage sensing signalaccording to the program designed and written in its OTPROM, so as tomake the microcontroller based electronic switch 1′ operate in on/offswitch control mode and dimming control mode accordingly. In the on/offswitch control mode when the microcontroller based electronic switch 1′is off, the program of the microcontroller 12′ generates a zero voltagefed to the gate of the uni-directional controllable semiconductorswitching element 14′ so as to turn off the switching element 14′. Inthe on/off switch control mode when the microcontroller based electronicswitch 1′ is on, the program of the microcontroller 12′ generates PWM(pulse-width-modulation) signal fed to the gate of the uni-directionalcontrollable semiconductor switching element 14′ so as to turn on theswitching element 14′ such that a fixed electric power is transmittedfrom the DC power source 3′ to the load 2′.

FIG. 8B is a voltage waveform diagram of the PWM signal according to anexemplary embodiment of the present disclosure. The PWM voltage signalis a square wave signal comprising a zero voltage (or low-voltage) and ahigh voltage, wherein the high voltage drives the uni-directionalcontrollable semiconductor switching element 14′ into conduction. If thetime length of the high voltage is T2 and the period of the PWM voltagesignal is T1, the average electric power delivered to the load 2′through the uni-directional controllable semiconductor switching element14′ is proportional to the ratio T₂/T₁, which is by definition the dutycycle of the PWM voltage signal and is denoted as δ=T₂/T₁. In the on/offswitch control mode, the program of the microcontroller 12′ generatesthe PWM voltage signal with maximum duty cycle to make themicrocontroller based electronic switch 1′ deliver the maximum averageelectric power to the load 2′. In the dimming control mode, the programof the microcontroller 12′ scans the low voltage sensing signal providedfrom the infrared ray sensor 11′. If the detected low voltage sensingsignal has different time length Ts, the program of the microcontroller12′ decreases the duty cycle of the PWM voltage signal in proportion toeach time length Ts, to gradually reduce the electric power sent to theload 2′.

In general, it is frequently to produce high-order harmonic interferencewhen a bi-directional controllable semiconductor switching element workswith conduction phase control technique to transmit AC electric powerthereof. To eliminate harmonic interference, the concept of the presentdisclosure can also be applied to the case of AC power source withoutusing triac element and zero-crossing-point detector.

FIG. 9 is a block diagram of a microcontroller based electronic switch1″ using an infrared ray sensor as a detection means for AC power sourceaccording to another one exemplary embodiment of the present disclosure.The microcontroller based electronic switch 1″ is connected to a load 2″and an AC power source 3″ in the serial fashion. Compared to FIG. 1, themicrocontroller based electronic switch 1″ comprises an infrared raysensor 11″, a microcontroller 12″, and three relays 15 a, 15 b, and 15 cconnected to different types of electrical impedances, for example,capacitors, respectively. Thus, the three relays 15 a, 15 b, and 15 ctogether with impedance elements 16 b and 16 c form three differentconducting paths with the different impedances. The three relays 15 a,15 b, and 15 c are arranged parallel to each other, and all of them areconnected to the load 2″ and the AC power source 3″. In other words,each of the three relays 15 a, 15 b, and 15 c is connected to the load2″ and the AC power source 3″ in the serial fashion. In practice, theload 2″ can be an electric fan, an AC-LED or an incandescent bulb.

The microcontroller 12″ has its three pins respectively connected to thegates of MOSFET (metal-oxide-semiconductor field-effect transistor),which drive respectively the three relays 15 a, 15 b, and 15 c. When thethree pins of the microcontroller 12″ simultaneously provide zerovoltage to the three MOSFETs, the three relays 15 a, 15 b, and 15 c arecut-off, and the microcontroller based electronic switch 1″ is cut-offor opened. When one pin of the microcontroller 12″ generates a highvoltage fed to one MOSFET, and the other two pins are zero voltage,merely one corresponding relay is in conduction state and the other tworelays are cutoff. Accordingly, when the first relay 15 a is inconduction state, a first-level electric power is transmitted directlyfrom the AC power source 3″ to the load 2″; when the second relay 15 bis in conduction state, a second-level electric power is transmittedthrough the impedance 16 b to the load 2″; when the third relay 15 c isin conduction state, a third-level electric power is transmitted throughthe impedance 16 c to the load 2″.

Referring to FIG. 3 and FIG. 9, the infrared ray sensor 11′ detects auser's hand, for instance, and converts the outcome into a low voltagesensing signal readable to the microcontroller 12″. The program of themicrocontroller 12″ controls the microcontroller based electronic switch1″ to operate in on/off switch control mode and in dimming control modeaccording to the detected infrared ray signal. In the on/off switchcontrol mode, when the microcontroller based electronic switch 1″ isoff, all three pins of the microcontroller 12″ respectively generateszero voltage fed to the three gates of MOSFETs so as to turn off allrelays 15 a-15 c. In the on/off switch control mode, when themicrocontroller based electronic switch 1″ is on, the microcontroller12″ generates a high voltage from one pin, and zero voltage from theother two pins, that only the first relay 15 a is in conduction state soas to deliver the first-level AC power to the load 2″. In dimmingcontrol mode, the program of the microcontroller 12″ scans the lowvoltage sensing signal provided by the infrared ray sensor 11′. Whenaccording to the low voltage sensing signal, the program of themicrocontroller 12′ generates a high voltage from the second or thethird pin and sets the other two pins at zero voltage, then one of therelays 15 b and 15 c is activated to be in conduction state, so that anAC electric power of the second-level or the third-level is transmittedto the load 2″. In other words, the microcontroller 12 generates zerovoltage or high voltage, respectively, to control the three relays 15 a,15 b, and 15 c to be opened or shorted in response to infrared raysensing signal.

Although the above description of the exemplary embodiments takesinfrared ray sensor as a means for detecting user's motion andgenerating sensing signal, the technology of the present disclosure hasno restriction on the types of detection method used. There are quite afew detection methods including touch or touchless means that can beapplied to the present invention of the multifunctional electronicswitch such as an infrared ray sensor (touchless interface), anelectrostatic induction sensor (also touchless interface), or a pushbutton sensor (direct touch interface). Each detection method mayrequire different motion control signals to be played by the user butthe core technology remains using the time length and format of thebinary sensing signals as the message carrier for transmitting theuser's choice of working mode. The microcontroller thereby decodes orinterprets the received message carrying sensing signals according tothe software program written in the OTPROM, recognizes the working modeselected by the user and activates the corresponding loop of subroutinefor performance execution.

Similar to the infrared ray sensor, the electrostatic induction sensorcan also create a touchless interface. The electrostatic inductionsensor generally comprises a copper sheet sensing unit with adequatelydesign shape and packaged with non-conductive material. Such coppersheet sensing unit is further electrically connected to a signalgenerating circuit similar to the infrared detection sensor unit. Thecopper sensing unit serves as an anode pole and the human body (normallyrefers to finger or hand) serves as a cathode pole to form aconfiguration of a capacitor. When the user's hand is approaching thecopper sensing unit, the electric charges are being gradually inducedand built up on the surface of the copper sensing unit with increasingdensity. Consequently, the copper sensing unit changes its electricstate from zero voltage state to a low voltage state. Such low voltagelevel will continue to grow as the user's hand moving closer and closerto the copper sensing unit till reaching a designed threshold pointwhich will trigger the detection circuit to generate a low voltagesensing signal. The distance between the copper sensing unit and thespace point where the threshold voltage incurs is defined as theeffective detecting zone. Similarly but reversely when the user's handis moving out from an operative point of the detecting zone of thecopper sensing unit, the voltage level will continue to decline tillpassing the designed threshold point which will trigger the cutoff ofthe low voltage sensing signal. The time length of the low voltagesensing signal so generated or in other words the time period betweenmoving in and moving out the effective detecting zone can be designed torepresent the selection of different working modes. If the time lengthis shorter than a preset time interval, it means the user's selection isto perform the on/off switch control mode; if the time length is longerthan a preset time interval, it means the user's selection is to performthe diming or power level control mode; if two or more low voltagesensing signals are consecutively generated within a preset timeinterval, in other words the user's hand moving in and out the detectingzone twice or swing across the detecting zone back and forth, it meansthe user's selection is to perform the delay timer management mode.

For direct touch detection sensors, such as a touch sensor or a pushbutton detection sensor, one touch on the conductive base or one instantpress on the control button within a preset time interval will triggerthe generation of a single sensing signal which will cause themicrocontroller to execute the subroutine of the on/off switch controlmode; a long touch on a conductive base or a long press on a controlbutton longer than the preset time interval will trigger the generationof a single sensing signal with time length longer than the preset timeinterval and the microcontroller responsively will execute thesubprogram of dimming control or power level control mode. Doubleinstant touches on the conductive base or double instant press on thecontrol button within a preset time interval will trigger the generationof two consecutive sensing signals which will cause the microcontrollerto execute the subroutine of delay timer management mode.

FIG. 10A and FIG. 10B together provide a good show case to prove thevalue of the user friendly concept of the present invention. Pictureshown in FIG. 10A is a popular piece of under cabinet light with LED aslight source. A manual on/off control switch is built on the right handside of the rectangular housing and a dimming knob is built on the frontpanel facing downward. Under cabinet lights are always installedunderneath the kitchen cabinets to provide sufficient indirectillumination to the user to do the kitchen work. The under cabinetlights and the kitchen cabinet are always installed at approximately thebreast level of the users for the convenience of doing kitchen work sothat the users can comfortably do the kitchen work without bending theirbody and having to work in a glaring environments. The current marketpiece as shown in FIG. 10A is not an user friendly device; the user hasto either use his or her hand to blindly search the locations of theon/off switch and the dimming knob or to bend his or her body to findthe exact locations of the two control units for operation.Additionally, the direct touch to control the on/off switch and dimmeralso brings up concerns of contagion and contamination in preparing foodin kitchen area and the housewives may have to wash their hands morefrequently than necessary.

FIG. 10B is an application of the present invention for a LED undercabinet light featured with a touchless interface between the user andthe under cabinet light. A motion of single swing of user's hand acrossthe detecting zone of the microcontroller based electronic switch 1 bwill activate the on/off switch mode alternately turning on and turningoff the under cabinet light 2 b. A motion of placing user's hand in thedetecting zone exceeding a preset time interval will activate the dimingmode to allow selection of brightness or power level. And a motion ofdouble swings of user's hand across the detecting zone within a presettime interval will activate the delay timer management mode to providethe user with a transitional illumination to leave the kitchen areabefore the light is completely turned off. The three basic working modescan be easily managed with simple motions played by the user without thehassles of having to blindly search the control switch and dimming knob,or to bend body to find the location of the control elements or tofrequently wash hands to avoid concerns of contagion and contaminationin preparing food. This is truly a very user friendly exemplaryembodiment of the present disclosure compared with what are currentlybeing sold in the market as shown in FIG. 10A.

FIG. 10C is another application of the present invention for a wallswitch construction electrically connected to a ceiling light for theperformance of three working modes. A motion of single swing across thedetecting zone in front of the wall switch 1 c by user's hand within apreset time interval will activate the on/off switch mode alternatelyturning on and turning off the ceiling light 2 c. A motion of placinguser's hand in front of the wall switch 1 c and stay in the detectingzone for a time period longer than a preset time interval will activatethe dimming mode to allow the user to select the desired brightness. Anda motion of double swings across the detecting zone within a preset timeinterval will activate the performance of the delay timer managementmode to provide the user a transitional illumination to leave for thenext location before the ceiling light is completely turned off. Thisnew wall switch when compared with conventional switch represents a veryuser friendly innovation from the easy operation point of view.Additionally, the delay timer mode helps to relieve the inconvenience ofeither having to live with a dark environment after turning off thelight or using a three way switch system to provide transitionalillumination. The conventional touch based wall switch is also a virusgathering spot because of use by many users and the issue of contagionand contamination is always a valid concern even outside the surgicalspace.

When the light source of the lighting load 2 is confined to the use ofan LED load, the compliance and satisfaction of a voltage operatingconstraint attributable to the unique electrical characteristics of theLED load is “critical” to a successful performance of an LED lightingdevice. Any LED lighting device failing to comply with the voltageoperating constraint attributable to the unique electricalcharacteristics of an LED load is bound to become an useless art. Thisis because the LED as a kind of solid state light source has verydifferent electrical characteristics for performing light emissioncompared with conventional light source such as incandescent bulbs orfluorescent bulbs. For instance, for a white light or blue light LEDthere exists a very narrow voltage domain ranging from a minimumthreshold voltage at 2.5 volts to a maximum working voltage at 3.3volts, in order to successfully operate the LED; in other words, when aforward voltage imposed on the LED is lower than the minimum thresholdvoltage, the LED is not conducted and therefore no light is emitted,when the forward voltage exceeds the maximum working voltage, the heatgenerated by a forward current could start damaging the construction ofthe LED. Therefore, the forward voltage imposed on the LED is requiredto operate between the minimum threshold voltage and the maximum workingvoltage. In respect to the LED load of the lighting load 2 the cut-involtage V_(t) of ACLEDs is technically also referred to as a minimumthreshold voltage attributable to PN junction semiconductor structuremanufactured in LEDs. More specifically, the LED is made with a PNjunction semiconductor structure “inherently” featured with three uniqueelectrical characteristics, the first characteristic is one-way electricconduction through the PN junction fabricated in the LED, the secondelectrical characteristic is a threshold voltage V_(th) required totrigger the LED to start emitting light and the third electricalcharacteristic is a maximum working voltage V_(max) allowed to impose onthe LED to avoid a thermal runaway to damage or burn out thesemiconductor construction of the LED. The described cut-in voltageV_(t) has the same meaning as the above mentioned threshold voltageV_(th) which is a more general term to be used for describing the secondelectrical characteristic of a PN junction semiconductor structure. Alsobecause the cut-in voltage V_(t) is specifically tied to forming aformula to transform the threshold voltage into a corresponding timephase of AC power for lighting control, it is necessary to use the termV_(th) as a neutral word for describing the LED electricalcharacteristics to avoid being confused with the specific applicationfor ACLED alone. Additionally, it is to be clarified that the term V_(m)is related to the amplitude of the instant maximum voltage of an ACpower source which has nothing to do with the third electricalcharacteristic Vmax of an LED load.

An LED chip is a small piece of semiconductor material with at least oneLED manufactured inside the semiconductor material. A plurality of LEDsmay be manufactured and packaged inside an LED chip for different levelsof wattage specification in order to meet different illumination need.For each LED chip designed with a different level of wattagespecification there always exists a narrow voltage domainV_(th)<V<V_(max), wherein V_(th) is the threshold voltage to enable theLED chip to start emitting light and V_(max) is the maximum workingvoltage allowed to impose on the LED chip to protect the LED chip frombeing damaged or burned out by the heat generated by a higher workingvoltage exceeding V_(max).

For an LED load configured with a plurality of the LED chips in any LEDlighting device, regardless such LED load being configured with ACLEDchips or DC LED chips, the working voltage of each single LED chip isrequired to operate in a domain between a threshold voltage V_(th) and amaximum working voltage V_(max) or V_(th)<V<V_(max) and the workingvoltage of the LED load comprising N pieces of LED chips connected inseries is therefore required to operate in a domain established by athreshold voltage N×V_(th) and a maximum working voltage N×V_(max) orN×V_(th)<V<N×V_(max), wherein N is the number of the LED chipselectrically connected in series. For any LED lighting device comprisingan LED load it is required that the LED load in conjunction with anadequate level of power source is configured with a combination of inseries and in parallel connections of LED chips such that the electriccurrent passing through each LED chip of the LED load remains at anadequate level such that a voltage V across each LED chip complies withan operating constraint of V_(th)<V<V_(max) featuring electricalcharacteristics of the LED chip or a voltage V across the LED loadconfigured with N number of LED chips connected in series complies withan operating constraint of N×V_(th)<V<N×V_(max). Such narrow operatingrange therefore posts an engineering challenge for a circuit designer tosuccessfully design an adequate level of power source and a reliablecircuitry configured with an adequate combination of in seriesconnection and in parallel connection of LED chips for operating ahigher power LED security light.

FIGS. 11A, 11B, 11C and 11D comprise 4 drawings schematically andrespectively showing a V-I relationship chart (Forward Current vs.Forward Voltage) for a white light LED chip from each of 4 different LEDmanufacturers; as can be seen from the chart when a forward voltage V isbelow a minimum forward voltage at around 2.5 volts, the LED chip is notconducted so the current I is zero, as the forward voltage exceeds 2.5volts the LED chip is activated to generate a current flow to emitlight, as the forward voltage continues to increase, the current Iincreases. exponentially at a much faster pace, at a maximum forwardvoltage around 3.3 volts the current I becomes 250 mA which generates aheat that could start damaging the PN junction of the LED chip. Theminimum forward voltage (the threshold voltage or cut-in voltage) andthe maximum forward voltage are readily available in the specificationsheets at each of LED manufacturers, such as Cree, Lumileds, Samsung,Osram, and etc. Different LED manufacturers may have slightly differentfigures due to manufacturing process but the deviations of differencesare negligible. The constraints of minimum forward voltage and maximumforward voltage represent physical properties inherent in any solidstate light source. They are necessary matter for configuring any LEDlighting products to ensure a normal performance of an LED load.

FIG. 12 is a data sheet showing data of the minimum forward voltages andmaximum forward voltages collected from various LED manufacturers. Theyare fundamental requirements for configuring any LED lighting controldevices to ensure a successful performance of any LED lighting device.

In summary, the compliance of voltage operating constraintV_(th)<V<V_(max) featuring electrical characteristics of an LED chip isa critical technology for ensuring a normal performance of the LED load.Failing to comply with such voltage operating constraint can quickly ageor seriously damage the semiconductor structure of the LED chip with aconsequence of quick lumens depreciation of the LED bulbs and theproduct lifetime being substantially shortened, which will beunacceptable to the consumers.

The compliance of the operating constraint V_(th)<V<V_(max) is anecessary matter for any LED lighting device though it is not an obviousmatter as it requires complicated technologies to calculate andcoordinate among an adequate level of power source, a control circuitryand a non-linear light emitting load. For conventional lighting loadsuch as incandescent bulb there exists no such operating constraint.This is why in the past years there had been many consumers complainingabout malfunction of LED bulbs that the consumers were frustrated withthe fast depreciation of lumens output and substantially shortenedproduct lifetime of the LED bulbs purchased and used. A good example wasa law suit case filed by the Federal Trade Commission on Sep. 7, 2010(Case No. SACV10-01333 JVS) for a complaint against a leading lightingmanufacturer for making deceptive LED lamps and making false claims withrespect to the life time of their LED lamps and a huge amount ofmonetary relief was claimed with the Court in the complaint.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present disclosure, without any intention to limit thescope of the present disclosure thereto. Various equivalent changes,alternations or modifications based on the claims of present disclosureare all consequently viewed as being embraced by the scope of thepresent disclosure.

What is claimed is:
 1. A microcontroller based electronic switch,comprising: a controllable switching element, electrically connectedbetween an LED load including a plurality of LEDs and a power source; atleast one detection device, for detecting at least one external controlsignal and convert said at least one external control signal into atleast one message carrying sensing signal with at least one signalformat; and a microcontroller designed to receive and interpret said atleast one message sensing signal generated by said at least onedetection device; wherein said at least one detection device iselectrically coupled with said microcontroller; wherein saidcontrollable switching element is electrically coupled with saidmicrocontroller, wherein said microcontroller outputs a control signalto control a conduction state or a cutoff state of said controllableswitching element according to said at least one message carryingsensing signal generated by said at least one detection device; whereinwhen said controllable switching element is in said conduction state,said microcontroller further controls an average electric powertransmission level from said power source to said LED load according tosaid at least one signal format of said at least one message carryingsensing signal received from said at least one detection device; whereinsaid at least one signal format of said at least one message carryingsensing signal is a short voltage signal, a long voltage signal or aplurality of short voltage signals, a plurality of long voltage signalsor a combination of said short voltage signal and said long voltagesignal; wherein said short voltage signal and said long voltage signalare defined either by a time length of a constant voltage signalgenerated or by said time length of a series of pulse signalsconsecutively generated; wherein when said microcontroller receives saidat least one message carrying sensing signal, said microcontrolleroperates to activate a corresponding process according to said at leastone signal format of said at least one message carrying sensing signalto perform at least one of various illumination performance modesincluding at least an on/off switch control mode, a dimming control modeand a delay shutoff mode; wherein said LED load connected to saidmicrocontroller based electronic switch is confined to a configurationwith LEDs in series and/or in parallel connections such that whenincorporated with a level setting of said DC power, an electric currentpassing through each LED of said LED load remains at a safety level suchthat a voltage V across each LED complies with an operating constraintof V_(th)<V<V_(max) featuring electrical characteristics of each LED,wherein V_(th) is a minimum threshold voltage required to trigger eachLED to start emitting light and V_(max) is a maximum operating voltageacross each LED to avoid a thermal damage or burning out of LEDconstruction; wherein when said LED load is configured with a pluralityof N number LEDs or N sets of LEDs electrically connected in series, aworking voltage V_(N) across said LED load is confined in a domainbetween a minimum voltage equal to the sum of the threshold voltages ofall LEDs or sets of LEDs electrically connected in series and a maximumvoltage equal to the sum of the maximum voltages of all LEDs or sets ofLEDs electrically connected in series, identically expressed asN×V_(th)<V_(N)<N×V_(max.); and wherein said microcontroller is aprogrammable integrated circuit device or an application specificintegrated circuit for generating said control signal.
 2. Themicrocontroller based electronic switch according to claim 1, whereinsaid detection device is configured with a touchless interface fordetecting said external control signal and converting said externalcontrol signal into said at least one message carrying sensing signalinterpretable to said microcontroller.
 3. The microcontroller basedelectronic switch according to claim 2, wherein said touchless interfaceis an active infrared ray motion sensor comprising a transmitter to emitinfrared light into an area to form a defined detection zone and areceiver to detect said infrared light reflected from an objectentering, staying in and leaving said defined detection zone, whereinwhen an object enters and leaves said defined detection zone, acircuitry responsively generates a first voltage sensing signal with atime length corresponding to a time interval of said object entering andstaying in said defined detection zone; wherein when said object leavessaid defined detection zone, said circuitry delivers a second voltagesignal, said first voltage sensing signal with said time length is abasic format for configuring said at least one message carrying sensingsignal to be delivered to said microcontroller for performing at leastone of said various illumination performance modes including at least anon/off switch control mode, a dimming control mode and a delay shutoffmode.
 4. The microcontroller based electronic switch according to claim2, wherein said touchless interface is a passive infrared ray motionsensor electrically coupled to said microcontroller for detecting amotion signal generated by an intruder into said at least one messagecarrying sensing signal with said at least one signal formatinterpretable to said microcontroller for performing at least one ofsaid various illumination performance modes including at least an on/offswitch control mode, a dimming control mode and a delay shutoff mode. 5.The microcontroller based electronic switch according to claim 2,wherein said touchless interface is an ultrasonic wave motion sensorcomprising a transmitter to transmit ultrasonic wave into an area toform a detection zone and a receiver to detect the ultrasonic wavereflected from an intruder entering said detection zone for detecting amotion signal and converting said motion signal into said at least onemessage sensing signal with said at least one signal formatinterpretable to said microcontroller for performing at least one ofsaid various illumination performance modes including at least an on/offswitch control mode, a dimming control mode and a delay shutoff mode. 6.The microcontroller based electronic switch according to claim 2,wherein said touchless interface is a microwave motion sensorelectrically coupled with said microcontroller, comprising a transmitterto transmit microwave signal into an area to form a detection zone and areceiver to detect said microwave signal reflected from an intruderentering said detection zone for detecting a motion signal andconverting said motion signal into said at least one message sensingsignal with said at least one signal format interpretable to saidmicrocontroller for performing at least one of said various illuminationperformance modes including at least an on/off switch control mode, adimming control mode and a delay shutoff mode.
 7. The microcontrollerbased electronic switch according to claim 2, wherein said touchlessinterface is a wireless remote control device electrically coupled tosaid microcontroller to receive and convert a wireless external controlsignal into said at least one message carrying sensing signal with saidat least one signal format interpretable to said microcontroller forperforming at least one of said various illumination modes including atleast an on/off switch control mode, a dimming control mode and a delayshutoff mode.
 8. The microcontroller based electronic switch accordingto claim 7, wherein said wireless remote control device is a Wi-Fiwireless signal receiver, a Blue Tooth wireless signal receiver, amicrowave wireless signal receiver or a millimeter wave wireless signalreceiver.
 9. The microcontroller based electronic switch according toclaim 1, wherein a wireless signal transmitter is further electricallycoupled with said microcontroller to convert said at least one messagecarrying sensing signal into at least one wireless control signal tosynchronously control at least one lighting performance of at least oneneighboring lighting apparatus.
 10. The microcontroller based electronicswitch according to claim 9, wherein said wireless signal transmitter isa Wi-Fi wireless signal transmitter, a Blue Tooth wireless signaltransmitter, a microwave wireless signal transmitter or a millimeterwave wireless signal transmitter.
 11. A lighting apparatus, comprising:a light emitting unit configured with an LED load including a pluralityof LEDs; a loading and power control unit; at least one detectiondevice, for detecting at least one external control signal andconverting said at least one external control signal into at least onemessage carrying sensing signal with at least one signal formatinterpretable to said microcontroller for performing at least oneillumination performance of said light emitting unit; and a wirelesssignal transmitter to convert said at least one message carrying sensingsignal into at least one wireless control signal to activate at leastone neighboring lighting apparatus for remotely and synchronouslyperforming said at least one illumination performance; wherein theloading and power control unit further comprises a microcontroller and aswitching circuitry, wherein said switching circuitry comprises at leastone semiconductor switching element, wherein said microcontroller iselectrically coupled with said at least one semiconductor switchingelement, said at least one detection device and said wireless signaltransmitter; wherein said microcontroller outputs a control signal tocontrol a conduction state or a cutoff state of said semiconductorswitching element according to said at least one signal format of saidat least one message carrying sensing signal received from said at leastone detection device; wherein when said at least one controllableswitching element is in said conduction state, said microcontrollerfurther controls an average electric power transmission level from saidpower source to said LED load according to said at least one signalformat of said at least one message carrying sensing signal receivedfrom said at least one detection device; wherein said at least onesignal format of said at least one message carrying sensing signal is ashort voltage signal, a long voltage signal or a plurality of shortvoltage signals, a plurality of long voltage signals or a combination ofsaid short voltage signal and said long voltage signal; wherein saidshort voltage signal and said long voltage signal are defined either bya time length of a constant voltage signal generated or by said timelength of a series of pulse signals consecutively generated; whereinwhen said microcontroller receives said at least one message carryingsensing signal, said microcontroller operates to activate acorresponding process for performing said at least one illuminationperformance of various illumination performance modes including at leastan on/off switch control mode, a dimming control mode and a delayshutoff mode; wherein said LED load is confined to a configuration withLEDs in series and/or in parallel connections such that whenincorporated with a level setting of said DC power, an electric currentpassing through each LED of said LED load remains at a safety level suchthat a voltage V across each LED complies with an operating constraintof V_(th)<V<V_(max) featuring electrical characteristics of each LED,wherein V_(th) is a minimum threshold voltage required to trigger eachLED to start emitting light and V_(max) is a maximum operating voltageacross each LED to avoid a thermal damage or burning out of LEDconstruction; wherein when said LED load is configured with a pluralityof N number LEDs or N sets of LEDs electrically connected in series, aworking voltage V_(N) across said LED load is confined in a domainbetween a minimum voltage equal to the sum of the threshold voltages ofall LEDs or sets of LEDs electrically connected in series and a maximumvoltage equal to the sum of the maximum voltages of all LEDs or sets ofLEDs electrically connected in series, identically expressed asN×V_(th)<V_(N)<N×V_(max.); and wherein said microcontroller is aprogrammable integrated circuit device or an application specificintegrated circuit for generating said control signal.
 12. The lightingapparatus according to claim 11, wherein said at least one detectiondevice is configured with a touchless interface for detecting said atleast one external control signal and converting said at least oneexternal control signal into said at least one message carrying sensingsignal interpretable to said microcontroller.
 13. The lighting apparatusaccording to claim 12, wherein said touchless interface is an activeinfrared ray sensor comprising a transmitter to emit infrared light intoan area to form a defined detection zone and a receiver to detect saidinfrared light reflected from an object entering, staying in and leavingsaid defined detection zone, wherein when an object enters and leavessaid defined detection zone, a circuitry responsively generates a firstvoltage sensing signal with a time length corresponding to a timeinterval of said object entering and staying in said defined detectionzone; wherein when said object leaves said defined detection zone, saidcircuitry delivers a second voltage signal, said first voltage sensingsignal with the time length is a basic format for configuring said atleast one message carrying sensing signal to be delivered to saidmicrocontroller for performing said at least one illuminationperformance of said various illumination performance modes including atleast said on/off switch control mode, said dimming control mode andsaid delay shutoff mode.
 14. The lighting apparatus according to claim12, wherein said touchless interface is a passive infrared ray motionsensor electrically coupled to said microcontroller for detecting andconverting a motion signal generated by an intruder into said at leastone message carrying sensing signal with said at least one signal formatinterpretable to said microcontroller for performing said at least oneillumination performance of said various illumination performance modesincluding at least said on/off switch control mode, said dimming controlmode and said delay shutoff mode.
 15. The lighting apparatus accordingto claim 12, wherein said touchless interface is an ultrasonic wavemotion sensor comprising a transmitter to transmit ultrasonic wave intoan area to form a detection zone and a receiver to detect saidultrasonic wave reflected from an intruder entering said detection zonefor detecting a motion signal and converting said motion signal intosaid at least one message sensing signal with said at least one signalformat interpretable to said microcontroller for performing said atleast one illumination performance of said various illuminationperformance modes including at least said on/off switch control mode,said dimming control mode and said delay shutoff mode.
 16. The lightingapparatus according to claim 12, wherein said touchless interface is amicrowave motion sensor electrically coupled with said microcontroller,comprising a transmitter to transmit microwave signal into an area toform a detection zone and a receiver to detect said microwave signalreflected from an intruder entering said detection zone for detecting amotion signal and converting said motion signal into said at least onemessage sensing signal with said at least one signal formatinterpretable to said microcontroller for performing said at least oneillumination performance of said various illumination performance modesincluding at least said on/off switch control mode, said dimming controlmode and said delay shutoff mode.
 17. The lighting apparatus accordingto claim 12, wherein said touchless interface is a wireless remotecontrol device electrically coupled to said microcontroller to receiveand convert a wireless external control signal into said at least onemessage carrying sensing signal with said at least one signal formatinterpretable to said microcontroller for performing said at least oneillumination performance of said various illumination performance modesincluding at least said on/off switch control mode, said dimming controlmode and said delay shutoff mode.
 18. The lighting apparatus accordingto claim 17, wherein said wireless external control signal is a BlueTooth wireless signal, a Wi-Fi wireless signal, a microwave wirelesssignal or a millimeter wave wireless signal.
 19. The lighting apparatusaccording claim 18, wherein said wireless external control signal isreceived from a smart phone or a mobile device, loaded with anapplication program (APP) or software program operable on a panel screenof said smart phone or said mobile device for controlling at least oneof said various illumination performance modes of said lightingapparatus.
 20. The lighting apparatus according to claim 18, whereinsaid microcontroller comprises a memory for saving or installing anapplication program (APP) or a software program, wherein saidapplication program or said software program from an internet or a cloudserver is downloaded for interpreting and executing said at least onemessage sensing signal from said wireless remote control device.
 21. Thelighting apparatus according to claim 18, wherein said wireless externalcontrol signal is received from a smart speaker to read, execute andconvert a voice instruction into said wireless external control signal.22. The lighting apparatus according to claim 11, wherein said wirelesssignal transmitter is a Blue Tooth wireless signal transmitter, a Wi-Fiwireless signal transmitter, a microwave wireless signal transmitter ora millimeter wave wireless signal transmitter.
 23. The lightingapparatus according claim 12, wherein said touchless interface is aphoto sensor for detecting a lumens level of a light intensity in adetection area and converting said lumens level into said at least onemessage sensing signal with said at least one signal formatinterpretable to said microcontroller for performing said at least oneillumination performance of said various illumination performance modesincluding at least said on/off switch control mode, said dimming controlmode and said delay shutoff mode.
 24. A lighting apparatus, comprising:a light emitting unit configured with an LED load including a pluralityof LEDs; a loading and power control unit comprising a microcontrollerand a switching circuitry; a light sensing unit, electrically coupledwith said microcontroller, for detecting a lumens value of an ambientlight in a detection area for controlling an on or off illuminationperformance of said light emitting unit; a motion sensing unit,electrically coupled with said microcontroller, for detecting a motionsignal to perform a high level illumination for a predetermined timeduration; and a wireless signal receiver, electrically coupled with saidmicrocontroller, for receiving at least one wireless external controlsignal and convert said at least one wireless external control signalinto at least one message carrying sensing signal with at least onesignal format interpretable to said microcontroller for executing atleast one illumination performance of various illumination performancesincluding at least an on/off performance, a dimming performance, a delayshutoff performance, a light sensitivity performance, a motionsensitivity performance or a switching performance between a motionsensing illumination mode and a dusk to dawn illumination mode; whereinsaid microcontroller comprises a memory for saving or installing anapplication program (APP) or a software program, wherein saidapplication program or said software program from an internet or a cloudserver is downloaded for interpreting and executing said at least onemessage sensing signal from said wireless signal receiver; wherein saidswitching circuitry comprises at least one semiconductor switchingelement; wherein said microcontroller is electrically coupled with saidat least one semiconductor switching element, said light sensing unit,said motion sensing unit and said wireless signal receiver; wherein saidmicrocontroller outputs a control signal to control a conduction stateof said at least one semiconductor switching element according to alight sensing signal from said light sensing unit or according to amotion sensing signal from said motion sensing unit; wherein when saidat least one semiconductor switching element is in said conductionstate, said microcontroller further control a conduction rate of said atleast one semiconductor switching element to control an average electricpower transmission level from said power source to said LED loadaccording to said at least one signal format of said at least onemessage carrying sensing signal received from said wireless signalreceiver; wherein said signal format of said at least one messagecarrying sensing signal is a short voltage signal, a long voltage signalor a plurality of short voltage signals, a plurality of long voltagesignals or a combination of said short voltage signal and said longvoltage signal; wherein said short voltage signal and said long voltagesignal are defined either by a time length of a constant voltage signalgenerated or by said time length of a series of pulse signalsconsecutively generated; wherein when said microcontroller receives saidat least one message carrying sensing signal, said microcontrolleroperates to activate a corresponding process according to said signalformat of said at least one message carrying sensing signal to performat least one of various illumination performances including at least anon/off switch performance, a dimming performance and a delay shutoffperformance, a light sensitivity performance, a motion sensitivityperformance, a performance switching between a motion sensing mode and adusk to dawn mode; wherein said LED load is confined to a configurationwith LEDs in series and/or in parallel connections such that whenincorporated with a level setting of said DC power, an electric currentpassing through each LED of said LED load remains at a safety level suchthat a voltage V across each LED complies with an operating constraintof V_(th)<V<V_(max) featuring electrical characteristics of each LED,wherein V_(th) is a minimum threshold voltage required to trigger eachLED to start emitting light and V_(max) is a maximum operating voltageacross each LED to avoid a thermal damage or burning out of LEDconstruction; wherein when said LED load is configured with a pluralityof N number LEDs or N sets of LEDs electrically connected in series, aworking voltage V_(N) across said LED load is confined in a domainbetween a minimum voltage equal to the sum of the threshold voltages ofall LEDs or sets of LEDs electrically connected in series and a maximumvoltage equal to the sum of the maximum voltages of all LEDs or sets ofLEDs electrically connected in series, identically expressed asN×V_(th)<V_(N)<N×V_(max); and wherein said microcontroller is aprogrammable integrated circuit device or an application specificintegrated circuit for generating the control signal.
 25. The lightingapparatus according to claim 24, wherein at dusk when said lumens valueof said ambient light is lower than a first predetermined value saidmicrocontroller operates to activate said motion sensing unit; whereinwhen said motion signal is detected by said motion sensing unit, saidmicrocontroller operates to conduct said at least one semiconductorswitching device to perform said high level illumination for saidpredetermined time duration; wherein at dawn when said lumens value ofsaid ambient light is higher than a second predetermined value saidmicrocontroller operates to switch off said light emitting unit.
 26. Thelighting apparatus according to claim 25, wherein at dusk when saidmotion sensing unit is activated said microcontroller operates tocontrol said at least one semiconductor switching device to deliver alow level electric power to said light emitting unit to generate a lowlevel illumination; wherein when said motion signal is detected by saidmotion sensing unit, said microcontroller operates to control said atleast one semiconductor switching device to deliver a high levelelectric power to said light emitting unit to perform said high levelillumination for said predetermined time duration.
 27. The lightingapparatus according to claim 24, wherein said at least one wirelessexternal control signal is a Blue Tooth wireless signal, a Wi-Fiwireless signal, a microwave wireless signal or a millimeter wavewireless signal.
 28. The lighting apparatus according to claim 25,wherein said at least one wireless external control signal is receivedfrom a smart phone or a mobile device, loaded with an applicationprogram (APP) or software program operable on a panel screen of saidsmart phone or said mobile device for controlling at least one of saidvarious illumination modes of said lighting apparatus.
 29. The lightingapparatus according to claim 25, wherein said at least one wirelessexternal control signal is received from a smart speaker to read,execute and convert a voice instruction into said wireless externalcontrol signal.
 30. The lighting apparatus according to claim 24,wherein said motion sensor is an active infrared ray motion sensor. 31.The lighting apparatus according to claim 24, wherein said motion sensoris a passive infrared ray motion sensor.
 32. The lighting apparatusaccording to claim 24, wherein said motion sensor is a microwave motionsensor.
 33. The lighting apparatus according to claim 24, wherein saidmotion sensor is an ultrasonic motion sensor.
 34. A lighting apparatus,comprising: a light emitting unit configured with an LED load includinga plurality of LEDs; a loading and power control unit including at leasta microcontroller and a switching circuitry; at least one detectiondevice, configured with a direct touch interface, for detecting anexternal control signal and converting said external control signal intoat least one first message carrying sensing signal with at least onesignal format interpretable to said microcontroller for activating atleast one illumination performance of various illumination performancesincluding at least an on/off performance, a dimming performance, a delayshutoff performance, a light sensitivity performance, a detectionsensitivity performance, a switching performance between operating twodifferent illumination modes; and a wireless signal receiver,electrically coupled with said microcontroller, for receiving a wirelessexternal control signal and convert said wireless external controlsignal into at least one second message carrying sensing signal withsaid at least one signal format interpretable to said microcontrollerfor activating said at least one illumination performance of saidvarious illumination performances including at least said on/offperformance, said dimming performance, said delay shutoff performance,said light sensitivity performance, said detection sensitivityperformance and said switching performance between operating twodifferent illumination modes; wherein said microcontroller comprises amemory for saving or installing an application program (APP) or asoftware program, wherein said application program or said softwareprogram from an internet or a cloud server is downloaded forinterpreting and executing said at least one second message sensingsignal from said wireless signal receiver; wherein said switchingcircuitry comprises at least one semiconductor switching element;wherein said microcontroller is electrically coupled with saidsemiconductor switching element, said at least one detection device andsaid wireless signal receiver; wherein said microcontroller outputs acontrol signal to control a conduction state of said at least onesemiconductor switching element according to said at least one firstmessage sensing signal or said at least one second message sensingsignal; wherein when said at least one semiconductor switching elementis in said conduction state, said microcontroller further control aconduction rate of said at least one semiconductor switching element tocontrol an average electric power transmission level from said powersource to said LED load according to said at least one first messagecarrying sensing signal received from said at least one detection deviceor according to said at least one second message sensing signal fromsaid wireless signal receiver; wherein said at least one signal formatof said at least one first message carrying sensing signal or said atleast one second message sensing signal is a short voltage signal, along voltage signal or a plurality of short voltage signals, a pluralityof long voltage signals or a combination of said short voltage signaland said long voltage signal; wherein said short voltage signal and saidlong voltage signal are defined either by a time length of a constantvoltage signal generated or by said time length of a series of pulsesignals consecutively generated; wherein when said microcontrollerreceives said at least one first message carrying sensing signal or saidat least one second message sensing signal, said microcontrolleroperates to activate a corresponding process according to said at leastone signal format of said at least one first message carrying sensingsignal or said at least one second message sensing signal to performsaid at least one illumination performance of said various illuminationperformances; wherein said microcontroller is a programmable integratedcircuit device or an application specific integrated circuit forgenerating the control signal; wherein said LED load is confined to aconfiguration with LEDs in series and/or in parallel connections suchthat when incorporated with a level setting of said DC power, anelectric current passing through each LED of said LED load remains at asafety level such that a voltage V across each LED complies with anoperating constraint of V_(th)<V<V_(max) featuring electricalcharacteristics of each LED, wherein V_(th) is a minimum thresholdvoltage required to trigger each LED to start emitting light and V_(max)is a maximum operating voltage across each LED to avoid a thermal damageor burning out of LED construction; wherein when said LED load isconfigured with a plurality of N number LEDs or N sets of LEDselectrically connected in series, a working voltage V_(N) across saidLED load is confined in a domain between a minimum voltage equal to thesum of the threshold voltages of all LEDs or sets of LEDs electricallyconnected in series and a maximum voltage equal to the sum of themaximum voltages of all LEDs or sets of LEDs electrically connected inseries, identically expressed as N×V_(th)<V_(N)<N×V_(max.); and whereinsaid microcontroller is a programmable integrated circuit device or anapplication specific integrated circuit for generating said controlsignal.
 35. The lighting apparatus according to claim 34, wherein saiddirect touch interface of said at least one detection device is a pushbutton switch, a touch sensor switch, a power interruption detectioncircuitry, a phase controller or a voltage divider.